Hitherto, materials for modeling and/or sculpturing composed of clays, used for the manual production of plastic representations or sculptures or the like of all types, for example, a piaster of Paris, an oil-based clay such as Plasticine(ex. U.S. Pat. No. 3,558,340, Japanese Patent Kokai No.53436/1977, No.36324/1979), an oil-based wheat flour(ex. Japanese Patent Kokai No.111128/1976, No.533/1977), a mixture of wood powder, hydrocarbon oil and rubber-reinforced styrene resin(ex. U.S. Pat. No. 4,624,976), a mixture of crushed paper or pulp and binding material(ex. Japanese Patent Kokai No.1117/1975, No.38427/1978), a mixture of synthesized latex, starch and bread powder (ex. U.S. Pat. No. 4,172,054), a mixture of polyvinyl alcohol powder and polyhydric alcohol(ex. Japanese Patent Kokai No.125446/1976), and the like, are widely well known.
These materials for modeling and/or sculpturing have been widely used by professional sculptors, artists, non-professional hobbyist including student or children and other workers as pliable materials.
Thus, for example, U.S. Pat. No. 3,558,340 describes a process of coating an object of oil or vax-based modeling clay which comprises several steps.
On the other hand, U.S. Pat. No. 3,883,456 describes a modeling compound which comprises polyvinyl chloride powder and alkyl polyglycolether and kaolin, and the like.
Furthermore, U.S. Pat. No. 4,336,071 describes a plastic compound which is deformable by hand and serves for the production of models, motifs and other kinds of plastic representations.
The plastic compound for modeling contains binding agents such as polyvinyl chloride or cellulose ether or ceresin wax, plasticizers and/or solvents, as well as fillers such as aluminum hydroxide.
The above-mentioned compounds can be molded with dies or by hands, and be sculptured with a chisel or a boaster and also be polished with a rasp or a sandpaper.
However, the above-mentioned compounds have many problems or disadvantages as described hereinafter.
For example, typically, the compounds cannot be used repeatedly and, for example, a work-piece or product in a partially broken condition cannot be repaired or re-shaped , meaning that a change from the softened state to the solidified state is typically irreversible.
Furthermore, fine hair cracks in a work-piece or product tend to occur over a long after it has solidified.
And also, thin or fine parts are extremely difficulty to shape because of weak flexural strength or self-supporting ability.
There is also a problem of dusting arising during handling, generally be requirement of a long time for drying or solidification.
Another disadvantage is the difficulty in painting with colored paint brightly or clearly, because of a typical lack of smoothness or of the above-mentioned fine hair cracks of the surface.
It is also difficult to color such work-piece or product to be colored clearly by blending pigments or dyes.
In order to overcome the above disadvantages, various kinds of resins have recently been proposed.
Examples of these include epoxy resins, polyurethane resins, acrylic resins, and polycaprolactones.
Of the above-mentioned resins, however, epoxy resins and polyurethane resins can be used only in special cases because of their irreversible hardenability.
Acrylic resins can only be sculptured or shaved, and their softening temperature is high, which considerably restricts their scope of application.
On the other hand, a lactone resin such as a polycaprolactone resin is one of the thermoplastic resins which can be softened at temperatures of approximately 60.degree. to 80.degree. C., so that the lactone resins have recently been used as a resin for modeling compound.
For example, the polycaprolactone resin for kneading and modeling compound was disclosed in Japanese unexamined patent publication(Kokai) No. 42679/1986[entitled "The Use of a Resin for Modeling Compound"].
Furthermore, Japanese unexamined patent publication(Kokai) No. 113457/1989 [entitled "A Resin composition and The Use of a resin for modeling compound"] and Japanese unexamined patent publication(Kokai) No. 213353/1989 [entitled "The Use of a resin for modeling compound"] disclose that the thermoplastic polycaprolactone is mixed with a chlorinated polyethylene or a chlorinated paraffin in order to delay the solidification process after softening.
Still further, Japanese unexamined patent publication(Kokai) No. 196090/1989 [entitled "The Use of a resin for modeling compound"] discloses that the thermoplastic polycaprolactone is mixed with a polycarbonate resin for lowering softening temperatures.
However, the caprolactone resin cannot be sculptured or shaved with a chisel or a boaster,etc., and cannot polished with a rasp or a sandpaper because of its hardness and hair cracks in spite of its moderate softening temperatures, that is, modeling temperatures and other excellent properties.